Random test, trying to understand feedrate

  • Hi guys, I tried something really wacky over the weekend. I thought I would do an experiment and figure out the lowest speed of printing.

    So I hooked up a duet to a few motors and stated with my test.

    Procedure I followed was simple, I set the step per mm to 25600 (200*128) which makes 1mm movement equal to one rotation of the motor. then I moved the motor 100 mm and noticed the motor did turn 100 turns.

    Now to check the various feedrates i sent a code G1 E100 Fxxx (xxx was varied from 1000 to 0.1)

    • so as expected at F1000, the motor just ended up slipping(just made a noise but did not move)

    • at F100, the motor moved 100 revolutions in 1 minute(perfect)

    • for F10, the motor took 3 min 20 seconds to complete 100 revolutions

    • then at F1and F0.1 the motor again took 3 min 20 seconds to complete 100 revolutions

    I was wondering why the motor doesn't move slower at feedrates lower than 30mm per min!

  • the duet has a lower limit for movement.

  • can that lower value be edited?? where can we find it??

  • as far as i understand, dc said that at the moment that is hard coded. but he was looking into changing that.

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